Officer pushed on storming of Lindt Cafe

A tactical operations officer has been forced to defend the time it took his team to storm the Lindt Cafe after hostage Tori Johnson was shot dead.

The Tactical Operations Unit veteran, identified as Delta Alpha, led one of the teams that breached the cafe after Mr Johnson was executed by gunman Man Haron Monis in the early hours of December 16, 2014.

An inquest into the 17-hour stand-off has heard his "Charlie" team took about 21 seconds to cross a small foyer and storm the stronghold through a side door.

Michael O'Connell SC, the barrister for the family of hostage Katrina Dawson, who was killed in crossfire, put to the officer that his team took "far too long".

After asking for security footage of the team's entry to be played at the inquest, Mr O'Connell pressed Delta Alpha on whether he now considered the delay unacceptable.

The tactical officer maintained there was little his team could have done differently.

He conceded their speed wasn't "optimal" and accepted his team had the shortest distance to cover and easiest access point.

"Given all the circumstances of what I've just viewed, your honour, I believe that is as fast as we could've gained entry," he said on Tuesday.

The officer said "with all things being perfect" his Charlie team - bursting in through the side door - would have entered quicker than the Alpha team, which barged through the Martin Place cafe's main doors.

Mr O'Connell pushed Delta Alpha on whether the outcome might have been different if police had engaged Monis from another position.

"There was a hostage that died as a result of police opening fire on Monis, you understand that," Mr O'Connell put to the witness.

"What I'm suggesting to you is that had Charlie and Delta been in there earlier, that might've changed the outcome."

The question was challenged by a barrister acting for the NSW Police and the witness was not required to respond.

The inquest has heard once he entered the cafe, Delta Alpha saw Monis directly behind another female hostage.

By the time the officer knelt to secure a clear shot, Monis had been shot dead.

Asked whether he would have taken a shot if Monis was still standing, Delta Alpha replied: "Yes, your honour, I would have."

Earlier, the officer was quizzed about the use of "flash bangs", which were thrown through the cafe's main doors to distract and disorient Monis.

"We've agreed that in the future, less sound and flash (devices) could have been deployed to achieve the desired result," he told the inquest.

Pressed further on the distraction devices, the officer conceded they were deployed in the wrong areas.